Mutual locking device for electromagnetic contactors

Abstract

A pair of closed contacts having moving contacts (27A), (27B) and fixed contacts (25A), (26A), (25B), (26B) are provided in a mutual locking device (3) and excitation circuits of two electromagnetic contactors which are inversely connected to respective closed contacts to effect electrical interlocking. The moving contacts (27A), (27B) are held by respective levers (36A), (36B) interlocked with driven members (5A), (5B) to be driven by corresponding moving contact supports of the electromagnetic contactors and opened when the electromagnetic contactor closes. Thus, electrical interlocking may be simultaneously effected using a mutual locking device for mechanically preventing two electromagnetic contactors reversibly connected from simultaneously closing.

What is claimed is: 
     
       1. A mutual locking device for electromagnetic contractors, comprising: a housing;   a pair of driven members, disposed in said housing, to be driven by corresponding moving contact supports of two electromagnetic contractors which are reversibly connected, said driven members having tilted edge faces at one end so as to form a cavity between said driven members and a backing member fixed to said housing and protruding from said housing towards the ends of said driven members having said tilted edge faces;   locking means, disposed in said cavity, for controlling the operations of said driven members so as to prevent the simultaneous closing of said electromagnetic contactors; and   a pair of switches, disposed in said housing, each comprising a moving contact connected by a lever interlocked with one of said driven members, and fixed contact facing said moving contact, wherein said moving contact provides an electrical connection between said fixed contacts when said one of said driven members to which said moving contact is connected is in a position at which the corresponding electromagnetic contactor is open.   
     
     
       2. The mutual locking device of claim 1, wherein said locking means comprises a locking pin which is caused to slide between said backing member and one of said driven members to prevent said one of the driven members from being driven by the corresponding electromagnetic contactor when the other one of said driven members is in a position at which the electromagnetic contactor corresponding thereto is closed. 
     
     
       3. The mutual locking device of claim 1, wherein the levers connecting the moving contacts with the driven members are also pivotably connected to said housing. 
     
     
       4. The mutual locking device of claim 1, wherein each lever is a trifurcated lever having a first arm pivotably connected to said housing, a second arm pivotably connected to one of said driven members, and a third arm connected to one of the moving contacts. 
     
     
       5. The mutual locking device of claim 4, wherein said third arm of each trifurcated lever is a slotted arm having said one of the moving contacts slidably disposed therein. 
     
     
       6. The mutual locking device of claim 5, wherein said on of the moving contacts is biased by a spring provided in said slotted arm of said trifurcated lever. 
     
     
       7. The mutual locking device of claim 1, wherein the fixed contacts are fixed to said housing. 
     
     
       8. The mutual locking device of claim 1, wherein said cavity is shaped as a pentagon wherein said backing member constitutes one side thereof, and an end portion of each said pair of driven members constitutes two sides of the pentagonal-shaped cavity. 
     
     
       9. A mutual locking device for electromagnetic contactors, comprising: a housing;   first shifting means, disposed in said housing, for shifting to one of two positions within said housing in response to corresponding movement of a contact support of a first electromagnetic contactor which is connected thereto;   second shifting means, disposed in said housing, for shifting to one of two positions within said housing in response to corresponding movement of a contact supports of a second electromagnetic contactor which is connected thereto, said first shifting means and said second shifting means having tilted edge faces at one end so as to form a cavity between said first shifting means, said second shifting means, and a backing member fixed to said housing and protruding from said housing towards the end of the first and second shifting means having said tilted edge faces;   locking means, disposed in said cavity, for controlling the operations of the first and second shifting means so as to prevent the simultaneous closing of the first and second electromagnetic contactors; and   switching means, disposed in said housing, for electrically disconnecting said first electromagnetic contactor when said second shifting means is shifted in response to a closing of said second electromagnetic contactor, and for electrically disconnecting said second electromagnetic contactor when said first shifting means is shifted in response to a closing of said first electromagnetic contactor.   
     
     
       10. The mutual locking device of claim 9, wherein said switching means comprises a pair of moving contacts connected by levers each interlocked with one of the first and second shifting means, and pairs of fixed contacts facing each moving contact, wherein each moving contact provides an electrical connection between said fixed contacts when one of the first and second shifting means to which said moving contact is connected is in a position at which the corresponding one of the first and second electromagnetic contactors is open. 
     
     
       11. The mutual locking device of claim 9, wherein said locking means comprises a locking pin which is caused to slide between said backing member and said first shifting means to prevent said first shifting means from being shifted by said first electromagnetic contactor when said second shifting means is in a position at which said second electromagnetic contactor is closed, and which is caused to slide between said backing member and said second shifting means to prevent said second shifting means from being shifted by said second electromagnetic contactor when said first shifting means is in a position at which said first electromagnetic contactor is closed. 
     
     
       12. The mutual locking device of claim 9, wherein the levers connecting the moving contacts with the first and second shifting means are also pivotably connected to said housing. 
     
     
       13. The mutual locking device of claim 9, wherein each lever is a trifurcated lever having a first arm pivotably connected to said housing, a second arm pivotably connected to one of the first and second shifting means, and a third arm connected to one of the moving contacts. 
     
     
       14. The mutual locking device of claim 13, wherein said third arm of each trifurcated lever is a slotted arm having said one of the moving contacts slidably disposed therein. 
     
     
       15. The mutual locking device of claim 14, wherein said on of the moving contacts is biased by a spring provided in said slotted arm of said trifurcated lever. 
     
     
       16. The mutual locking device of claim 9, wherein the fixed contacts are fixed to said housing. 
     
     
       17. The mutual locking device of claim 9, wherein said cavity is shaped as a pentagon wherein said backing member constitutes a first side thereof, an end portion of said first shifting means constitutes second and third sides of the pentagonal-shaped cavity, and an end portion of said second shifting means constitutes fourth and fifth sides of the pentagonal-shaped cavity.